IBIC2014 - List of Authors (Gassner, D.M.)

Paper	Title	Page
MOPF04	RHIC Injection Transport Beam Emittance Measurements	45
	J.Y. Huang Duke University, Durham, North Carolina, USA D.M. Gassner, M.G. Minty, S. Tepikian, P. Thieberger, N. Tsoupas, C.M. Zimmer BNL, Upton, Long Island, New York, USA
	The Alternating Gradient Synchrotron (AGS)-to-Relativistic Heavy Ion Collider (RHIC) transfer line, abbreviated AtR, is an integral component for the transfer of proton and heavy ion bunches from the AGS to RHIC. In this study, using 23.8 GeV proton beams, we focused on factors that may affect the accuracy of emittance measurements that provide information on the quality of the beam injected into RHIC. The method of emittance measurement uses fluorescent screens in the AtR. The factors that may affect the measurement are: background noise, calibration, resolution, and dispersive corrections. Ideal video Offset (black level, brightness) and Gain (contrast) settings were determined for consistent initial conditions in the Flag Profile Monitor (FPM) application. Using this information, we also updated spatial calibrations for the FPM using corresponding fiducial markings and sketches. Resolution error was determined using the Modulation Transfer Function amplitude. To measure the contribution of the beam’s dispersion, we conducted a scan of beam position and size at relevant Beam Position Monitors (BPMs) and Video Profile Monitors (VPMs, or “flags”) by varying the extraction energy with a scan of the RF frequency in the AGS. The combined effects of these factors resulted in slight variations in emittance values, with further analysis suggesting potential discrepancies in the current model of the beam line’s focusing properties. In the process of testing various contributing factors, a system of checks has been established for future studies, providing an efficient, standardized, and reproducible procedure that might encourage greater reliance on the transfer line’s emittance and beam parameter measurements.
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MOPF05	Instrumentation for the Proposed Low Energy RHIC Electron Cooling Project with Energy Recovery	49
	D.M. Gassner, A.V. Fedotov, R.L. Hulsart, D. Kayran, V. Litvinenko, R.J. Michnoff, T.A. Miller, M.G. Minty, I. Pinayev, M. Wilinski BNL, Upton, Long Island, New York, USA
	Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy There is a strong interest in running RHIC at low ion beam energies of 7.7-20 GeV/nucleon [1]; this is much lower than the typical operations with 100 GeV/nucleon. The primary motivation for this effort is to explore the existence and location of the critical point on the QCD phase diagram. Electron cooling can increase the average integrated luminosity and increase the length of the stored lifetime. A cooling system is being designed that will provide a 30 – 50 mA electron beam with adequate quality and an energy range of 1.6 – 5 MeV. The cooling facility is planned to be inside the RHIC tunnel. The injector will include a 704 MHz SRF gun, a 704 MHz 5-cell SRF cavity followed by a normal conducting 2.1 GHz cavity. Electrons from the injector will be transported to the Yellow RHIC ring to allow electron-ion co-propagation for ~20 m, then a 180 degree U-turn electron transport so the same electron beam can similarly cool the Blue ion beam. After the cooling process with electron beam energies of 1.6 to 2 MeV, the electrons will be transported directly to a dump. When cooling with higher energy electrons between 2 and 5 MeV, after the cooling process, they will be routed through the acceleration cavity again to allow energy recovery and less power deposited in the dump. Special consideration is given to ensure overlap of electron and ion beams in the cooling section and achieving the requirements needed for cooling. The instrumentation systems described will include current transformers, beam position monitors, profile monitors, an emittance slit station, recombination and beam loss monitors.
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MOPF08	Beam Profile Measurements in the RHIC Electron Lens using a Pinhole Detector and YAG Screen	59
	T.A. Miller, M.R. Costanzo, W. Fischer, B. Frak, D.M. Gassner, X. Gu, A.I. Pikin BNL, Upton, Long Island, New York, USA
	Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy The electron lenses installed in RHIC are equipped with two independent transverse beam profiling systems, namely the Pinhole Detector and YAG screen. A small Faraday cup, with a 0.2mm pinhole mask, intercepts the electron beam while a pre-programmed routine automatically raster scans the beam across the detector face. The collected charge is integrated, digitized and stored in an image type data file that represents the electron beam density. This plungeable detector shares space in the vacuum chamber with a plunging YAG:Ce crystal coated with aluminum. A view port at the downstream extremity of the Collector allows a GigE camera, fitted with a zoom lens, to image the crystal and digitize the profile of a beam pulse. Custom beam profiling software has been written to import both beam image files (pinhole and YAG) and fully characterize the transverse beam profile. The results of these profile measurements are presented here along with a description of the system and operational features. * W. Fischer, et al, "… head-on beam-beam compensation in RHIC", ICFA (BB3013), CERN (2013). **T. Miller, et al, “… eLens pin-hole detector and YAG…“, BIW2012, Newport News, VA, TUPG039
	Poster MOPF08 [6.731 MB]
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MOPD01	RHIC p-Carbon Polarimeter Target Lifetime Issue	124
	H. Huang, E.C. Aschenauer, G. Atoian, A. Bazilevsky, O. Eyser, A. Fernando, D.M. Gassner, D. Kalinkin, J. Kewisch, G.J. Mahler, Y. Makdisi, S. Nemesure, A. Poblaguev, W.B. Schmidke, D. Steski, T. Tsang, K. Yip, A. Zelenski BNL, Upton, Long Island, New York, USA I.G. Alekseev, D. Svirida ITEP, Moscow, Russia
	Funding: Work performed under contract No. DE-AC02-98CH1-886 with the auspices of the DOE of United States RHIC polarized proton operation requires fast and reliable proton polarimeter for polarization monitoring during stores. Polarimeters based on p-Carbon elastic scattering in the Coulomb Nuclear Interference(CNI) region has been used. Two polarimeters are installed in each of the two collider rings and they are capable to provide important polarization profile information. The polarimeter also provides valuable information for polarization loss on the energy ramp. As the intensity increases over years, the carbon target lifetime is getting shorter and target replacement during operation is necessary. Simulations and experiment tests have been done to address the target lifetime issue. This paper summarizes the recent operation and the target test results.
	Poster MOPD01 [10.776 MB]
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MOPD02	The Electron Backscattering Detector (eBSD), a New Tool for the Precise Mutual Alignment of the Electron and Ion Beams in Electron Lenses	129
	P. Thieberger, Z. Altinbas, C. Carlson, C. Chasman, M.R. Costanzo, C. Degen, K.A. Drees, W. Fischer, D.M. Gassner, X. Gu, K. Hamdi, J. Hock, Y. Luo, A. Marusic, T.A. Miller, M.G. Minty, C. Montag, A.I. Pikin, S.M. White BNL, Upton, Long Island, New York, USA
	Funding: Work supported by Brookhaven Science Associates, LLC under contract No. DE-AC02-98CH10886 with the U.S. Department of Energy The Relativistic Heavy Ion Collider (RHIC) electron lenses, being commissioned to attain higher polarized proton-proton luminosities by partially compensating the beam-beam effect, require good alignment of the electron and proton beams. These beams propagating in opposite directions in a 5T solenoid have a typical rms width of 300 microns and need to overlap each other over an interaction length of about 2 m with deviations of less than ~50 microns. A new beam diagnostic tool to achieve and maintain this alignment is based on detecting electrons that are backscattered in close encounters with protons. Maximizing the intensity of these electrons ensures optimum beam overlap. The successful commissioning of these devices using 100 GeV/amu gold beams is described. Future developments are discussed that will further improve the sensitivity to small angular deviations.
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WEPF26	The Brookhaven LINAC Isotope Production Facility (BLIP) Raster Scanning Upgrade	608
	R.J. Michnoff, Z. Altinbas, P. Cerniglia, R. Connolly, C. Cullen, C. Degen, D.M. Gassner, R.L. Hulsart, R.F. Lambiase, L.F. Mausner, D. Raparia, P. Thieberger, M. Wilinski BNL, Upton, Long Island, New York, USA
	Brookhaven National Laboratory’s BLIP facility produces radioisotopes for the nuclear medicine community and industry, and performs research to develop new radioisotopes desired by nuclear medicine investigators. A raster scanning system is being installed to provide a better distribution of the H⁻ beam on the targets, allow higher beam intensities to be used, and ultimately increase production yield of the isotopes. The upgrade consists of horizontal and vertical dipole magnets sinusoidally driven at 5 kHz with 90 deg phase separation to produce a circular raster pattern, and a suite of new instrumentation devices to measure beam characteristics and allow adequate machine protection. The instrumentation systems include multi-wire profile monitors, a laser profile monitor, beam current transformers, and a beam position monitor. An overview of the upgrade and project status will be presented. Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy
	Poster WEPF26 [2.002 MB]
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Paper

Title

Page

RHIC Injection Transport Beam Emittance Measurements

45

J.Y. Huang
Duke University, Durham, North Carolina, USA
D.M. Gassner, M.G. Minty, S. Tepikian, P. Thieberger, N. Tsoupas, C.M. Zimmer
BNL, Upton, Long Island, New York, USA

The Alternating Gradient Synchrotron (AGS)-to-Relativistic Heavy Ion Collider (RHIC) transfer line, abbreviated AtR, is an integral component for the transfer of proton and heavy ion bunches from the AGS to RHIC. In this study, using 23.8 GeV proton beams, we focused on factors that may affect the accuracy of emittance measurements that provide information on the quality of the beam injected into RHIC. The method of emittance measurement uses fluorescent screens in the AtR. The factors that may affect the measurement are: background noise, calibration, resolution, and dispersive corrections. Ideal video Offset (black level, brightness) and Gain (contrast) settings were determined for consistent initial conditions in the Flag Profile Monitor (FPM) application. Using this information, we also updated spatial calibrations for the FPM using corresponding fiducial markings and sketches. Resolution error was determined using the Modulation Transfer Function amplitude. To measure the contribution of the beam’s dispersion, we conducted a scan of beam position and size at relevant Beam Position Monitors (BPMs) and Video Profile Monitors (VPMs, or “flags”) by varying the extraction energy with a scan of the RF frequency in the AGS. The combined effects of these factors resulted in slight variations in emittance values, with further analysis suggesting potential discrepancies in the current model of the beam line’s focusing properties. In the process of testing various contributing factors, a system of checks has been established for future studies, providing an efficient, standardized, and reproducible procedure that might encourage greater reliance on the transfer line’s emittance and beam parameter measurements.

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MOPF05

Instrumentation for the Proposed Low Energy RHIC Electron Cooling Project with Energy Recovery

49

D.M. Gassner, A.V. Fedotov, R.L. Hulsart, D. Kayran, V. Litvinenko, R.J. Michnoff, T.A. Miller, M.G. Minty, I. Pinayev, M. Wilinski
BNL, Upton, Long Island, New York, USA

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy
There is a strong interest in running RHIC at low ion beam energies of 7.7-20 GeV/nucleon [1]; this is much lower than the typical operations with 100 GeV/nucleon. The primary motivation for this effort is to explore the existence and location of the critical point on the QCD phase diagram. Electron cooling can increase the average integrated luminosity and increase the length of the stored lifetime. A cooling system is being designed that will provide a 30 – 50 mA electron beam with adequate quality and an energy range of 1.6 – 5 MeV. The cooling facility is planned to be inside the RHIC tunnel. The injector will include a 704 MHz SRF gun, a 704 MHz 5-cell SRF cavity followed by a normal conducting 2.1 GHz cavity. Electrons from the injector will be transported to the Yellow RHIC ring to allow electron-ion co-propagation for ~20 m, then a 180 degree U-turn electron transport so the same electron beam can similarly cool the Blue ion beam. After the cooling process with electron beam energies of 1.6 to 2 MeV, the electrons will be transported directly to a dump. When cooling with higher energy electrons between 2 and 5 MeV, after the cooling process, they will be routed through the acceleration cavity again to allow energy recovery and less power deposited in the dump. Special consideration is given to ensure overlap of electron and ion beams in the cooling section and achieving the requirements needed for cooling. The instrumentation systems described will include current transformers, beam position monitors, profile monitors, an emittance slit station, recombination and beam loss monitors.

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MOPF08

Beam Profile Measurements in the RHIC Electron Lens using a Pinhole Detector and YAG Screen

59

T.A. Miller, M.R. Costanzo, W. Fischer, B. Frak, D.M. Gassner, X. Gu, A.I. Pikin
BNL, Upton, Long Island, New York, USA

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy
The electron lenses installed in RHIC are equipped with two independent transverse beam profiling systems, namely the Pinhole Detector and YAG screen. A small Faraday cup, with a 0.2mm pinhole mask, intercepts the electron beam while a pre-programmed routine automatically raster scans the beam across the detector face. The collected charge is integrated, digitized and stored in an image type data file that represents the electron beam density. This plungeable detector shares space in the vacuum chamber with a plunging YAG:Ce crystal coated with aluminum. A view port at the downstream extremity of the Collector allows a GigE camera, fitted with a zoom lens, to image the crystal and digitize the profile of a beam pulse. Custom beam profiling software has been written to import both beam image files (pinhole and YAG) and fully characterize the transverse beam profile. The results of these profile measurements are presented here along with a description of the system and operational features.
* W. Fischer, et al, "… head-on beam-beam compensation in RHIC", ICFA (BB3013), CERN (2013).
**T. Miller, et al, “… eLens pin-hole detector and YAG…“, BIW2012, Newport News, VA, TUPG039

Poster MOPF08 [6.731 MB]

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MOPD01

RHIC p-Carbon Polarimeter Target Lifetime Issue

124

H. Huang, E.C. Aschenauer, G. Atoian, A. Bazilevsky, O. Eyser, A. Fernando, D.M. Gassner, D. Kalinkin, J. Kewisch, G.J. Mahler, Y. Makdisi, S. Nemesure, A. Poblaguev, W.B. Schmidke, D. Steski, T. Tsang, K. Yip, A. Zelenski
BNL, Upton, Long Island, New York, USA
I.G. Alekseev, D. Svirida
ITEP, Moscow, Russia

Funding: Work performed under contract No. DE-AC02-98CH1-886 with the auspices of the DOE of United States
RHIC polarized proton operation requires fast and reliable proton polarimeter for polarization monitoring during stores. Polarimeters based on p-Carbon elastic scattering in the Coulomb Nuclear Interference(CNI) region has been used. Two polarimeters are installed in each of the two collider rings and they are capable to provide important polarization profile information. The polarimeter also provides valuable information for polarization loss on the energy ramp. As the intensity increases over years, the carbon target lifetime is getting shorter and target replacement during operation is necessary. Simulations and experiment tests have been done to address the target lifetime issue. This paper summarizes the recent operation and the target test results.

Poster MOPD01 [10.776 MB]

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MOPD02

The Electron Backscattering Detector (eBSD), a New Tool for the Precise Mutual Alignment of the Electron and Ion Beams in Electron Lenses

129

P. Thieberger, Z. Altinbas, C. Carlson, C. Chasman, M.R. Costanzo, C. Degen, K.A. Drees, W. Fischer, D.M. Gassner, X. Gu, K. Hamdi, J. Hock, Y. Luo, A. Marusic, T.A. Miller, M.G. Minty, C. Montag, A.I. Pikin, S.M. White
BNL, Upton, Long Island, New York, USA

Funding: Work supported by Brookhaven Science Associates, LLC under contract No. DE-AC02-98CH10886 with the U.S. Department of Energy
The Relativistic Heavy Ion Collider (RHIC) electron lenses, being commissioned to attain higher polarized proton-proton luminosities by partially compensating the beam-beam effect, require good alignment of the electron and proton beams. These beams propagating in opposite directions in a 5T solenoid have a typical rms width of 300 microns and need to overlap each other over an interaction length of about 2 m with deviations of less than ~50 microns. A new beam diagnostic tool to achieve and maintain this alignment is based on detecting electrons that are backscattered in close encounters with protons. Maximizing the intensity of these electrons ensures optimum beam overlap. The successful commissioning of these devices using 100 GeV/amu gold beams is described. Future developments are discussed that will further improve the sensitivity to small angular deviations.

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WEPF26

The Brookhaven LINAC Isotope Production Facility (BLIP) Raster Scanning Upgrade

608

R.J. Michnoff, Z. Altinbas, P. Cerniglia, R. Connolly, C. Cullen, C. Degen, D.M. Gassner, R.L. Hulsart, R.F. Lambiase, L.F. Mausner, D. Raparia, P. Thieberger, M. Wilinski
BNL, Upton, Long Island, New York, USA

Brookhaven National Laboratory’s BLIP facility produces radioisotopes for the nuclear medicine community and industry, and performs research to develop new radioisotopes desired by nuclear medicine investigators. A raster scanning system is being installed to provide a better distribution of the H⁻ beam on the targets, allow higher beam intensities to be used, and ultimately increase production yield of the isotopes. The upgrade consists of horizontal and vertical dipole magnets sinusoidally driven at 5 kHz with 90 deg phase separation to produce a circular raster pattern, and a suite of new instrumentation devices to measure beam characteristics and allow adequate machine protection. The instrumentation systems include multi-wire profile monitors, a laser profile monitor, beam current transformers, and a beam position monitor. An overview of the upgrade and project status will be presented.
Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy

Poster WEPF26 [2.002 MB]

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